Yes, it's just glycerin by-product, not glycerin with methanol. Thanks for bringing that up; I forget that some people automatically think that glycerin contains methanol.

I've tried other ways of eradicating aphids, like spraying with soap solution, but none ever worked as effectively as the glycerin solution. One application and they're gone, and no apparent harm to the plants, though I wasn't expecting any. I especially like the non toxic, biodegradable properties of the glycerin since it does not compromise the organic cultivation.